The unknown, at the other end of the wire, began giving Mrs. Damon
a description of just what papers he wanted, and how to mail them
to him. He gave an address that Ned recognized as that of a cigar
store, where many persons received their mail under assumed names.
The postal authorities had, for a long time, tried to get evidence
against it

"That's going to make it hard to get him, when he comes for the
papers," thought Ned. "He's a foxy criminal, all right. But I
guess Tom will turn the trick."

Mrs. Damon was carefully noting down the address. She really
intended to send the papers, if it proved that there was no other
way in which she could secure the release of her husband. But she
did not count on all of Tom's plans. "Why doesn't he develop that
plate?" thought Ned. "He'll be too late, in spite of his airship.
That fellow will skip."

It was at that moment that Tom came into the library. He moved
cautiously, for he realized that a loud sound in the room would
carry to the man at the other end of the wire. Tom motioned for
Ned to come to him. He held out a dripping photographic plate.

"I know. It didn't sound a bit like Peters over the 'phone, but
there's his picture, all right!"

Tom held up the plate. There, imprinted on it by the wonderful
power of the young inventor's latest appliance, was the image of
the rascally promoter. As plainly as in life he was shown, even to
his silk hat and the flower in his button-hole. He was in a
telephone booth--that much could be told from the photograph that
had been transmitted over the wire, but which booth could not be
said--they were nearly all alike.

"Yes, I know. You were right, and I was wrong. But I did not
recognize his voice. It was very hoarse. He must have a bad cold."
Later this was learned to have been the case. "There's no time to
lose," whispered Tom, while Mrs. Damon was doing her best to
prolong the conversation in order to hold the man at the other end
of the wire. "Ned, get central on the other telephone, and see
where this call came from. Then we'll get there as fast as the
airship will take us."

A second and temporary telephone line had been installed in the
Damon home, and on this Ned was soon talking, while Tom, putting
the photographic plate away for future use, rushed out to get his
airship in shape for a quick flight. He had modified his plans.
Instead of having a detective take a print of the photo telephone
image, and make the arrest, Tom was going to try to capture Peters
himself. He believed he could do it. One look at the wet plate was
enough. He knew Peters, though it upset some of his theories to
learn that it was the promoter who was responsible for Mr. Damon's
disappearance.

The man at the other end of the wire was evidently getting
impatient. Possibly he suspected some trick. "I've got to go now,"
he called to Mrs. Damon. "If I don't get those papers in the
morning it will be the worse for Mr. Damon."

By this time Ned had gotten into communication with the manager of
the central telephone exchange, and had learned the location of
the instrument Peters was using. It was about a mile from the one
near the sawmill.

"Come on!" called Tom to his chum, as the latter gave him this
information. "The Firefly is tuned up for a hundred miles an hour!
We'll be there in ten minutes! We must catch him red-handed, if
possible!"

"He's gone!" gasped Mrs. Damon as she came to the outer door, and
watched Tom and Ned taking their places in the airship, while Koku
prepared to twirl the propellers.

"See if you can't get him back," suggested the young inventor.
"Ask Central to ring that number again. We'll be there in a jiffy.
Maybe he'll come to the telephone again. Or he may even call up
his partners and tell them the game is working his way. Try to get
him back, Mrs. Damon."

"Well, you were right. I was off, that time," admitted Tom, as he
guided his powerful craft above the trees. "I was willing to admit
that he had something to do with Mr. Damon's financial trouble,
but as for kidnapping him--well, you never can tell."

They drove on at a breath-catching pace, and it seemed hardly a
minute after leaving Mrs. Damon's house before Tom called:

The airship swooped down, to the great astonishment of some
workmen nearby.

Hardly had the wheels ceased revolving on the ground, as Tom made
a quick landing, than he was out of his seat, and running toward
the telephone. He knew the place at once from having heard Ned's
description, and besides, this was one of the places where he had
installed his apparatus.

Into the store Tom burst, and made a rush for the 'phone booth. He
threw open the door. The place was empty!

"The man--the man who was telephoning!" Tom called to the
proprietor of the place.